The goal of the project is to develop a novel sensor technology platform based on carbon nanotube electronic sensor device, which could be integrated into a biochip and used for detection and analysis of biomolecules in samples from blood, saliva and other body fluids, as well as studies of protein-protein and protein-small molecule interactions in the research laboratory. The fundamental principle of the technology has been demonstrated by Professor Hongjie Dai's group at Stanford University, showing that the electrical resistance change of a nanotube can be detected when a biological event such as antigen-antibody binding occurs on the surface of the nanotubes. In the proposed electronic sensor array each nanotube sensor will be chemically functionalized and immobilized with biomolecules to provide selectivity and specificity for detection of various analytes. The detection scheme is based on changes in the nanotube's electrical conductance due to changes of the electrostatic environment upon analyte binding. Such detection system requires no expensive detection equipment, such as lasers, or fluorescence labeling of analytes. Instead the detection is based on a simple direct electrical readout. The objective of this program is to demonstrate the feasibility of a nanosensor providing the sensitivity and selectivity for detection of a biological marker, which is integrated into an electrical circuitry for easy readout. The specific aims include: (1) the fabrication of electrical devices containing semiconducting single-walled carbon nanotubes; this involves controlled growth of nanotubes on wafers by chemical vapor deposition and construction of electrodes and electrical circuits on wafers by semiconductor technology, (2) the functionalization of the nanotubes in the electrical devices for immobilization of biomolecules onto the nanotubes. A variety of functionalization strategies will be investigated to minimize non-specific adsorption and to maximize selectivity. Successful demonstration of the proposed nanotube-based biosensor will have a significant impact on a number of commercial sectors and help establish the United States as leader in the emerging field of nanotechnology. [unreadable] [unreadable]